Our Rabbis taught: Twelve questions did the Alexandrians address to Rabbi Yehoshua . Three were of hokhmah (knowledge), three were matters of aggada, three were mere nonsense and three were matters of conduct.
Rabbi Yehoshua was one of the leaders of the Jewish community in the generation that followed the destruction of the second Temple. He was famous in Israel and throughout the world, not only for his erudition in matters of Jewish law, but also for his expertise in the sciences and in general knowledge, from astronomy to zoology. He traveled to Rome on numerous occasions as a member of official leadership delegations, where he had occasion to appear before the Caesar. Among the topics discussed in the course of those meetings were questions of science and general knowledge.
In the course of his travels, Rabbi Yehoshua met with many of the leading non-Jewish thinkers of his time. We find stories of meetings between him and the elders of Athens as well as those of Alexandria – two of the centers of worldly knowledge of those times – as we see in our Gemara.
Rashi explains that the questions about hokhmah or knowledge that are presented in the Gemara all relate to matters of Jewish law (they focus on laws of ritual purity, priestly marriage and sacrifices brought by a leper). It is clear from their questions that the Alexandrians were knowledgeable – and interested – in Jewish law and the methods used by the Sages to derive these laws. Others explain that hokhmah refers to the “revealed” parts of the Torah, in contrast with the hidden, or esoteric knowledge of the Torah.